


Stickshifts and Safetybelts

by thisiswherethefishlives



Category: Agents of S.H.I.E.L.D. (TV)
Genre: Age Difference, Anal Sex, Car Sex, Dubious Consent, FitzMack - Freeform, Inspired by GIF, M/M, NSFW, NSFW GIF, fitz isn't underage but he is significantly younger than mack, unprotected sex
Language: English
Status: Completed
Published: 2015-04-24
Updated: 2015-04-24
Packaged: 2018-03-25 13:30:33
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,637
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3812296
Author URL: https://archiveofourown.org/users/thisiswherethefishlives/pseuds/thisiswherethefishlives
Summary: <blockquote class="userstuff">
              <p>There's sweat beading on his brow, and there's grease worked into his hands so deep that he'll probably never get it out, but Mack doesn't have it in him to be self conscious as he slicks up his fingers. Keeping his eyes on his hands, he doesn't allow himself to look up just yet - he's not ready, and if this is going to happen there's gotta be some semblance of control to hang on to.</p>
<p>As it is, he's grasping at the edge of his sanity, pushed further off with every gasped breath and whimper let out by the boy beneath him. There's no escaping the fact there, because Leo is a boy. Barely seventeen and too brilliant for his own good, too gorgeous to resist any longer.</p>
            </blockquote>





	Stickshifts and Safetybelts

**Author's Note:**

> Inspired by the below [gif](http://i.giphy.com/l3nWdxblIzaGAkUfu.gif).  
> Things to be aware of: Fitz is 17 in the fic, Mack is 34 - the age difference mirrors that of Iain de Caestecker and Henry Simmons, and it is exploited to fit the caption on the gif. If that age difference squicks you out, this is not the fic for you.  
> I am marking this as dubcon due to the age difference to be safe rather than sorry. 

* * *

  


* * *

There's sweat beading on his brow and there's grease worked into his hands so deep that he'll probably never get it out, but Mack doesn't have it in him to be self conscious as he slicks up his fingers. Keeping his eyes on his hands, he doesn't allow himself to look up just yet - he's not ready, and if this is going to happen there's gotta be some semblance of control to hang on to.  

As it is, he's grasping at the edge of his sanity, pushed further off with every gasped breath and whimper let out by the boy beneath him. There's no escaping the fact there, because Leo _is_ a boy. Barely seventeen and too brilliant for his own good, too gorgeous to resist any longer.

Mack allows his thumb, slick with lube and rough with calluses, to trace along the edge of Leo's rim. The boy gasps, and Mack can't resist looking up at his face any longer. He's going to Hell, and he's not sure how he's supposed to look Mr. Fitz in the eyes when he clocks in for tomorrow's shift... but those are problems for later because right now Leo's lips are bitten and pink, still shiny from where Mack had licked at them earlier. As wrong as this may be, there's no way Mack would undo this moment, not now that he's got Leo spread on the driver’s seat with his trousers and pants thrown in the back seat. Certainly not now that the boy's looking back at him with so much trust and just enough impatience to have him thrusting back against the pad of Mack's thumb.

"I can take it, Mack. I- I can take it, I've been practicing. All for you." Each word out of Leo's lips comes out winded and desperate, as if he's been running for ages only to stumble into the quenching cool of Mack's presence. "Please, Mack. I need-"

Slowly, Mack pushes in with his thumb, eyes drawn back down to where he's slowly pressing inside past the tight ring of muscle into where Leo runs hottest. It’s just a shallow press before he’s bringing his hand back again, and Mack finds that he needs to anchor the boy to the seat with a steady press of his free hand to Leo’s hip when the boy bucks up at the loss. There’s a sharp whine that sounds nothing like the boy, and it’s with a rush that Mack realizes that he’s the reason Leo’s been reduced to a writhing bundle of nerves and want. “Hush now, I’ve got you, Turbo.” Mack can’t keep the affection out of his voice anymore, gave up trying weeks ago, and he’s thankful now that he stopped fighting it.

It’s almost tender, the way he presses soft circles into Leo’s hip with his thumb, and he can feel the boy relax underneath his attention. As much as Mack just wants to take and claim the boy, there’s a larger part of him that wants to make it good for him, wants to set the standard high… it’s selfish, because there’s a large part of Mack that wants to be the only one to see Leo like this, panting and flushed and so, so gorgeous. He pushes the thought away and focuses instead of pressing a thick finger into Leo, watches as each knuckle slowly disappears. It’s tempting to just stay here, pressed into the tight v of Leo’s legs as he fingers the boy open, but it’s clear that Mack’s the only one that has the patience for taking it slow.

“Mack, please give me another. I spent all-,” the boy’s words fall to the wayside as Mack eases in another finger. Leo’s tight, and hot, and so perfect that Mack can’t resist leaning forward to nibble at the boy’s lips before licking deep into his mouth.

Kissing Leo is a revelation. It’s heady and rich, and Mack feels drunk with each press of lips and brush of tongues. He can still taste the mint of Leo’s toothpaste, chases after the flavor as he works the boy open on two fingers, scissoring and thrusting until he feels confident about easing in a third. The fact that Leo can take this much already lends truth to the filthy things he had taken to describing to Mack on their daily commutes to the university. It’s clear now that the boy hadn’t been over exaggerating when he described how he would spread himself open on three fingers before fucking himself with all kinds of toys. Maybe Mack shouldn’t have chalked it up to teenaged bravado when Leo told him it was all in preparation for Mack.

It would probably be easier if he could forget, with three fingers slowly fucking into Leo, just how young the boy is… it would be easier on Mack’s soul if he wasn’t already aware of the seventeen years between them and the implicit trust that the Fitz family had put in Mack to make sure their son was in safe hands… but he’s no longer worried about Heaven and Hell, not when it comes to this _thing_ he’s allowed to build between the two of them over the past year. Mack doesn’t know where this is going, doesn’t know if it’s going to be a one-time thing or an ongoing descent into madness, but he’s come to far to be concerned about anything other than the slick, tight heat of Leo’s ass and how good it’s going to feel to fuck into it.

Gently, so gently, Mack pulls his fingers out before reaching back for the lube, spreading more over his fingers to warm it before slicking up his cock. Glancing up, he can see Leo’s eyes are glazed as they follow the motion of his hand. He can’t contain his smirk when Leo unconsciously spreads his legs wider.

“Alright, Turbo. Here’s how it’s gonna go. I’m gonna give you what you’ve been begging for. I’m gonna fuck you, and I’m gonna fill you up with everything I have to give, but if you call me Mack we’re gonna stop.” Mack can see the pout forming on Leo’s face. Gently, he brings his hand up to the boys face, stroking his cheek softly before tracing his lips with his fingertips. “No pouting, Turbo. You told me what you wanted, and I’m going to give it to you.”

He’s not prepared for the kitten lick Leo places against his thumb, or the way the boy’s eyes darken even further. “Yes, Mr. Mackenzie.”

Mack’s not proud of how hard he gets hearing Leo call him that, but he can’t deny that it’s what finally pushed him into action. He’s never gone by anything other than Mack with the Fitz family, and he was more than fine with Leo growing up doing the same, but hearing ‘ _Mr. Mackenzie_ ’ in Leo’s soft voice and lilting accent reminds him just how dirty/wrong/hot this all is. There’s another lick at his fingers, but there will be time for that later.

He’s gonna make time for that later, that’s for damn sure.

For now, he settles his hand back at the boy’s hip, careful to grip him just firmly enough to keep the wriggling at bay. Mack has no desire to bruise the boy… at least, not yet. Carefully, he lines his cock up, making sure to pause before pushing in.

“Are you sure that this is what you want, Turbo?” It’s amazing that Mack’s voice is as steady as it is, because he feels raw and wanting, but this isn’t something he’s prepared to take from Leo without his outright consent.

"Yeah... _yes_. I want this, want you." Leo's voice is breathless with want, but his voice is steady and true. It's all the confirmation Mack needs.

"I want you too, Turbo. I'm gonna make you feel so good."

He’s pushing in then, and it feels like time just stops. Everything is narrowed down to this point of connection as Mack sinks deeper in. It’s all too warm, too tight, too good, and for all that time has stopped for Mack, the little keen that Leo lets out brings him back to the present where he is completely sheathed in the boy beneath him.

Mack can’t help but take pride in the way the flush on Leo’s cheeks has spread down his neck to his chest. He’s so pretty like this, underneath Mack and panting, all strawberries and cream skin and blue, blue eyes.

There’s a part of Mack that just wants to stay here, taking in the beauty of the moment… but there’s a larger, more reasonable side to Mack that reminds him that they are pulled to the side of the road - the longer he takes worshipping the boy beneath him just leaves them more likely to get caught.

He’s jostled out of his thoughts when Leo bucks his hips into Mack’s.

“Are you going to fuck me, Mr. Mackenzie? I already know you think I’m pretty, you don’t have to spend all day looking at me to prove it.”

Pulling back slightly, Mack thrusts back in. It’s shallow, but there’s enough momentum behind the movement to have Leo scrabbling for something to hold onto. Mack repeats the motion until the snarky smirk has been wiped off Leo’s face, doesn’t stop until the boy’s eyes are glossed over and his lips are swollen and so pink from the way he’s been biting at them.

“How’s that, Turbo? Is that what you wanted?”

“Almost, I-” the rest of his thought process cuts off with another one of Mack’s thrusts, and it’s cute… more than cute, that Mack has the power to fuck the thoughts out of this brilliant boy, but more than anything - more than any ego trip - Mack wants to make this good for Leo. He brings his hips to a standstill before carefully, gently reaching up to brush a curl back from Leo’s forehead.

“What do you need?”

It’s a simple question, probably too simple, because what Mack _really_ means to say is that he will give everything he can to the boy. He’ll do anything to make Leo Fitz happy. It’s not something that Mack’s ready to say yet, he’s not ready to let Leo know just how much Mack is in his sway, but he’s pretty sure the kid knows anyway from the way he’s smiling up at Mack.

“Would you kiss me?”

Mack’s struck in that moment by how completely, totally gone he is over this kid. Here he is, prepared to give Leo the world, and he asks for a kiss.

Adjusting his stance slightly, Mack pulls Leo closer to the edge of the car seat before carefully lifting him into a sitting position. It’s all eye contact and soft touches, and Mack just knows that he’s not going to last long like this. Leo’s eyes shutter closed when Mack leans in to claim his lips, and it’s such a precious, chaste moment - pure and hopeful, and such a contrast to the way Mack’s fucking into the boy.

He leaves a hand wrapped around Leo’s shoulder to steady him as Mack wraps his free hand around the boy’s length. Everything about Leo is soft and smooth and so, so warm. His cock is no exception; flushed pink, thick and slick already from his own pre-come, Mack strokes him slowly to match his own thrusts. He can’t help but imagine how good it would feel to be split by the boy - to be fucked, marked by his kid that’s just barely old enough to vote.

It’s only when the boy starts groaning his consent that Mack realizes he’s been talking out loud.

“Yeah… _yeah_ , I would make you mine. No one else’s, just mine… and it would be so good, Mack. We would be so- _ugh_ , so good.”

“Shhhhhhhhh, c’mon baby.” Mack doesn’t mean for the endearment to tumble from his lips, but there it is. Something about the fact that he’s Mack again, not ‘Mr. Mackenzie’... suddenly this isn’t a game anymore. It’s the realest thing Mack’s ever known.

Leo’s body is loose, relaxed completely into their motions, lips full and tender, hips meeting each of Mack’s thrusts, fingers twitching against Mack’s biceps every time Mack hits that spot deep inside. “C’mon, baby, I want you to come all on me. Can you do that for me? Mark me up, Turbo. C’mon.”

Leo’s lashes flutter in response to Mack’s words and Mack can feel the boy’s thighs tensing up on either side of him; he just wants it to be so good for Leo, wants him to come back again and again, wants him to know that Mack will take care of him. He doesn’t tighten his grip around Leo’s cock, but he does drag his thumb over and around the head, reveling in just how much the boy’s leaking pre-come. It’s hot, but Mack knows now that this isn’t going to last much further. He’s so close to the edge, each thrust bringing him closer to spilling deep into his boy and- oh. _Oh_.

With a final thrust, Mack spills deep inside of Leo and it’s good. It’s so good, but Leo’s not there with him, and _that_? That’s not okay.

It takes a minute to find the lube again, but it’s the work of moments to get it poured into his palm. Mack’s careful to warm it up, working it between his fingers before taking a firm hold of Leo again. The high flush on Leo’s cheeks is everything right now, and Mack revels in every gasp and groan that he pulls out of his lover until the boy’s hips stutter up and his back bows in climax.

He’s beautiful.

“So beautiful, Leo. Beautiful and all mine.”

At Mack’s words, Leo just smiles, and he’s perfect - he’s always perfect, but Mack knows that nothing will ever compare to this moment.

“Yeah, Mack. M’yours…”

They stay there, covered in come and an overwhelming feeling of new beginnings and completion, until Leo starts to wriggle out of Mack’s hold in discomfort. Carefully, Mack pulls out before leaning over the boy to open the glove compartment for the wipes he keeps there. He wipes Leo down first, helping the boy back into his pants before giving himself a cursory wipe. There will be time to shower later, but for now they have places to go.

“You gonna be okay to get to class, Turbo?”

Leo shoots him a cheeky grin as he does up the button to his jeans, leaning forward to claim Mack’s mouth in a kiss, this one much less chaste than the others before. It’s a clash of tongues and teeth and want, and for all of Mack’s prior experience, nothing has come close to the rush he gets from Leo.

“Mhmm, I’ll be just fine. Can’t say that I won’t be distracted thinking about the ride home though.”

And that… yeah, that’s all the incentive Mack needs to swat the boy into the passenger seat so he can climb into the driver’s seat. He had been so caught up in the here and now, and the vague sense of _forever…_ but hearing from Leo’s mouth that this is going to happen again? That’s everything.

He starts the car, allowing the purr of the motor to fill the space between them, hands steady on the wheel and his heart still beating just a little too hard. Whatever this is, wherever this goes, Mack can’t allow himself to focus on the negatives; the danger, the age difference, the fact that he could lose his job if Mr. Fitz ever found out… as long as Leo wants to ride beside him, that’s all that matters.

“C’mon, then. Let’s get you to school.”


End file.
